The winter solstice is here today (Dec. 21), marking the shortest day and longest night of the year for the Northern Hemisphere.

As the astronomical start of winter, today is the moment the sun reaches its lowest point in the sky as seen from Earth. At noon, it appears directly over the Tropic of Capricorn, a latitude of 23.5 degrees south, creating the least daylight of the year for the Northern Hemisphere, which is tilted as far from the sun as it gets.

This turning point lasts only an instant. The exact moment of the 2025 winter solstice occurs today at 10:03 a.m. EST (1503 GMT), officially ushering in the new season.

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With the sun tracking low across the horizon, its rays arrive at a shallow angle, spreading light over a larger area and reducing heating. It’s this lower solar angle, not our distance from the sun, that drives the coldest months of the year. But from this point forward, daylight will slowly begin to increase as we begin the slow march toward spring.

Earth’s seasons exist because our planet is tilted by 23.5 degrees on its axis. As Earth orbits the sun, different hemispheres lean toward or away from it, changing the intensity and duration of sunlight. When the Northern Hemisphere tilts toward the sun, we get summer; when it tilts away — as it does now — we have winter.

Meanwhile, the Southern Hemisphere is experiencing its summer solstice today, enjoying the longest day of the year.

Although many assume winter corresponds to Earth being farther from the sun, the opposite is true. Earth actually reaches perihelion, its closest point to the sun, early next month on Jan. 3, 2026. At that moment, our planet will sit about 91.4 million miles (147.1 million kilometers) from the sun, slightly closer than its average distance of 93 million miles (149.6 million km).

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Many cultures mark the winter solstice as a moment of renewal and the symbolic return of light. Starting tomorrow, daylight begins to grow again, a reminder that brighter, warmer days are on the way.

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Netflix is one of the best streaming services available and Stranger Things is one of its flagship shows. So, to celebrate the final season coming to the small screen, and the holiday season too, we’ve rounded up the best Stranger Things gifts on the market.

Here, you’ll find a range of gifts from clothes to collectibles to trinkets, replicas and more. The holiday season is here and the final episodes of Stranger Things will air on Christmas Day and New Year’s Eve, so there’s never been a better time to search for the best Stranger Things gifts out there. While we haven’t reviewed any of the items we’ve highlighted, we wouldn’t include them if we didn’t recommend having them.

With Stranger Things being one of the most anticipated sci-fi TV shows around, there’s a huge range of Stranger Things gifts available. If you don’t find something suitable though, you can always check out the best streaming deals, Fallout gifts, 10 best space gifts under $100, or something a little different like the best star projectors and best Lego Star Wars sets ahead of the holidays. But, for the best Stranger Things gifts on the market, scroll down below.

Best Stranger Things Gifts We Recommend

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A paraplegic engineer from Germany blasted off on a dream-come-true rocket ride with five other passengers on Saturday, leaving her wheelchair behind to float in space while beholding Earth from on high.

Severely injured in a mountain bike accident seven years ago, Michaela Benthaus became the first wheelchair user in space, launching from west Texas with Jeff Bezos’s company Blue Origin. She was accompanied by a retired SpaceX executive also born in Germany, Hans Koenigsmann, who helped organize and, along with Blue Origin, sponsored her trip. Their ticket prices were not divulged.

An ecstatic Benthaus said she laughed all the way up – the capsule soared more than 65 miles (105km) – and tried to turn upside down once in space.

“It was the coolest experience,” she said shortly after landing.

The 10-minute space-skimming flight required only minor adjustments to accommodate Benthaus, according to the company. That’s because the autonomous New Shepard capsule was designed with accessibility in mind, “making it more accessible to a wider range of people than traditional spaceflight”, said Blue Origin’s Jake Mills, an engineer who trained the crew and assisted them on launch day.

Among Blue Origin’s previous space tourists: those with limited mobility and impaired sight or hearing, and a pair of 90-year-olds.

For Benthaus, Blue Origin added a patient transfer board so she could scoot between the capsule’s hatch and her seat. The recovery team also unrolled a carpet on the desert floor after touchdown, providing immediate access to her wheelchair, which she left behind at liftoff. She practiced in advance, with Koenigsmann taking part with the design and testing. An elevator was already in place at the launch pad to ascend the seven stories to the capsule perched atop the rocket.

Benthaus, 33, part of the European Space Agency’s graduate trainee program in the Netherlands, experienced snippets of weightlessness during a parabolic airplane flight out of Houston in 2022. Less than two years later, she took part in a two-week simulated space mission in Poland.

“I never really thought that going on a spaceflight would be a real option for me because even as like a super healthy person, it’s like so competitive, right?” she told the Associated Press ahead of the flight.

Her accident dashed whatever hope she had. “There is like no history of people with disabilities flying to space,” she said.

When Koenigsmann approached her last year about the possibility of flying on Blue Origin and experiencing more than three minutes of weightlessness on a space hop, Benthaus thought there might be a misunderstanding. But there wasn’t, and she immediately signed on.

It’s a private mission for Benthaus with no involvement by the European Space Agency (ESA), which this year cleared reserve astronaut John McFall, an amputee, for a future flight to the International Space Station. The former British Paralympian lost his right leg in a motorcycle accident when he was a teenager.

An injured spinal cord means Benthaus can’t walk at all, unlike McFall, who uses a prosthetic leg and could evacuate a space capsule in an emergency at touchdown by himself. Koenigsmann was designated before flight as her emergency helper; he and Mills lifted her out of the capsule and down the short flight of steps at flight’s end.

“You should never give up on your dreams, right?” Benthaus urged after touchdown.

Benthaus was adamant about doing as much as she could by herself. Her goal is to make not only space accessible to disabled people, but to improve accessibility on Earth too.

While getting lots of positive feedback within “my space bubble”, she said outsiders aren’t always as inclusive.

“I really hope it’s opening up for people like me, like I hope I’m only the start,” she said.

Besides Koenigsmann, Benthaus shared the ride with business executives and investors, and a computer scientist. They raised Blue Origin’s list of space travelers to 86.

Bezos, the billionaire founder of Amazon, created Blue Origin in 2000 and launched its first passenger spaceflight in 2021. The company has since delivered spacecraft to orbit from Cape Canaveral, Florida, using the bigger and more powerful New Glenn rocket, and is working to send landers to the moon.

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A rare dinosaur discovery sheds new light on the evolution of flight. Fossils of dinosaurs found with well-preserved feathers suggest that some of these animals were no longer capable of flight. The researchers explain that even a detail as subtle as how feathers are replaced can dramatically reshape our understanding of how flight evolved, revealing […]



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As Avatar: Fire and Ash hits cinemas worldwide, we figured now is the perfect time to step back and take a look at director James Cameron’s entire sci-fi slate, ranking them from worst to best.

The Canadian filmmaker has carved out an iconic status in the movie industry for his visual effects artistry, incredible research, and extraordinary storytelling – and while The Terminator might be the first sci-fi title that comes to mind, it actually wasn’t his debut.

A short film called Xenogenesis was the launching pad of his directorial work, but at 12 minutes long, it won’t feature in the rankings. Still, it’s a piece of cinematic history that illustrates Cameron’s nearly 50-year love affair with the sci-fi genre.

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We’d be incredibly surprised if you didn’t recognise every single movie on the list below, and you’ll also notice some recurring actors that Cameron hires, with both Sigourney Weaver and Michael Biehn appearing in three movies each.

We’re not adding Avatar: Fire & Ash to the list just yet — we need to stew on it before we can firmly slot it into the rankings — but otherwise, here’s every James Cameron sci-fi movie ranked, worst to best.

6. The Abyss

The Abyss | Remastered 4K In Theaters | Official Trailer – YouTube

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Release date: August 9, 1989 | Cast: Ed Harris, Mary Elizabeth Mastrantonio, Michael Biehn | Rotten Tomatoes: 76% on the Tomatometer

The deep sea is scary enough, but you know what makes it even scarier? Finding aliens down there. Unfortunately for Ed Harris and Mary Elizabeth Mastrantonio, — starring as estranged husband and wife, Bud and Lindsey — their passion for diving takes them on a horrifyingly claustrophobic adventure to the depths of the ocean.

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When a nuclear submarine disappears, the crew of a civilian oil rig goes on a search and rescue mission with jaw-dropping consequences. For James Cameron, who’d already risen to fame with The Terminator and Aliens, it was a watery shift that no one saw coming. And, unfortunately, it wasn’t a massive hit at the time (though it still won an Oscar for best visual effects).

More recently, though, it’s become a well-loved sci-fi pick, with a revised (and extended to a hefty 171 minutes) version that viewers are even more eager to dive right into and experience the unexpected.

Cameron tells a fantastically tense sci-fi tale, gripping audiences with the heart-wrenching relationship of Bud and Lindsey, and the romantic tension that builds throughout is a welcome reprieve from the intense water-dwelling extraterrestrials. Nothing like a fear for human life to put your love into perspective, right?

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5. Avatar: The Way of Water

Avatar: The Way of Water | Official Trailer – YouTube

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Release date: December 16, 2022 | Cast: Sam Worthington, Zoe Saldana, Sigourney Weaver, Stephen Lang | Rotten Tomatoes: 76% on the Tomatometer

13 years after Avatar stormed onto the big screen, the sequel arrived. And it says a lot about Cameron’s abilities as a director that it felt like no time had passed at all. Jake Sully has fully integrated himself into his life as a Na’vi, still with Neytiri, and now with a family to look after. Unfortunately, they don’t get their ‘happily ever after’ as humanity returns to Pandora. So instead, they get to star in another exhilarating action movie.

Once again, Cameron intertwines the pillars of his directorial work: outstanding visuals, epic storytelling, and an unwavering ability to create tension. VFX is the cornerstone of a movie like Avatar, transforming actors into their Na’vi form and formulating their lives in a whole new world. Cameron’s always had bigger plans for Avatar, though, telling Variety: “We were working on three scripts and then it turned into four.”

In fact, Avatar: Fire and Ash is the second half of the original The Way of Water script. With plans for another sequel, that kind of freedom and ability to plan ahead is something most directors can only dream of. For Cameron, it’s a well-deserved reality.

4. The Terminator

THE TERMINATOR (1984) | Official Trailer | MGM – YouTube

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Release date: October 26, 1984 | Cast: Arnold Schwarzenegger, Michael Biehn, Linda Hamilton | Rotten Tomatoes: 90% on the Tomatometer

We’ve been talking about The Terminator for years. I even ranked The Terminator movies back in 2022 – and it’s still an absolute pleasure to discuss. And yet, it’s in fourth place on this list, a testament to just how strong Cameron’s sci-fi chops are.

Arnold Schwarzenegger stars as The Terminator, a time-travelling cyborg on a mission to take out one Sarah Connor. Why? Well, because one day she’s destined to become the mother of humankind’s salvation, and as far as The Terminator is concerned, that can’t happen.

Not only is The Terminator a bona fide sci-fi classic, but it’s the first major work of Cameron’s career, and its success was the spark to sent him on the path to directorial superstardom. Up until this point, Cameron had been mainly working in visual effects, and he poured everything he’d learned up to this point into The Terminator, bringing the entire story to life in a way that’s still incredible to watch to this day.

3. Avatar

Avatar | Official Trailer (HD) | 20th Century FOX – YouTube

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Release date: December 18, 2009 | Cast: Sam Worthington, Zoe Saldaña, Sigourney Weaver, Michelle Rodriguez | Rotten Tomatoes: 81% on the Tomatometer

Cinematically breathtaking, deeply immersive, and the highest-grossing movie of all time, Avatar is a piece of cinematic history. It feels almost criminal to place it third, but perhaps Cameron shouldn’t be so good at directing sci-fi movies. Avatar is the first movie I saw in 3D in the cinema, and I distinctly remember feeling like if I just reached out, I could touch the falling leaves of Pandora.

Avatar sees Jake Sully, a paraplegic veteran, on a mission to the moon Pandora, in an entirely new form, adopting that of the Na’vi people. But while he’s there to gather a rare resource, he falls in love and vows to protect Pandora and the Na’vi as his own.

The groundbreaking use of 3D technology was one of the main reasons Avatar was such and is still such a huge success, but beyond that, it just tells such a compelling and relatable tale.

2. Terminator 2: Judgment Day

Terminator 2: Judgment Day (1991) Trailer #1 | Movieclips Classic Trailers – YouTube

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Release date: July 3, 1991 | Cast: Arnold Schwarzenegger, Linda Hamilton, Robert Patrick | Rotten Tomatoes: 91% on the Tomatometer

Terminator 2: Judgment Day holds the top spot amongst the best Terminator movies, and it’s also arguably one of the best sequels to any movie, ever. Acting as Cameron’s own conclusion to the Terminator franchise (disputes over rights saw his directorial ties severed after this), it’s a sequel that took everything about the first movie and made it even better.

In Terminator 2, Arnie returns as the T-800, but this time as a reprogrammed good cyborg protecting a young John Connor. That leaves a gap for a bad cyborg to take his place, and that’s where Robert Patrick’s T-1000 comes into play.

Action-packed and full of robotic terror, Terminator 2 is the T-800’s redemption arc perfectly translated onto the big screen with Cameron’s dedication to telling a perfectly paced story. And, by this point, Cameron has sci-fi thrills down to a tee, building on his work from the first Terminator movie. It’s not quite the best sci-fi movie he’s ever made, though; that title goes to…

1. Aliens

Aliens (1986) Trailer #1 | Movieclips Classic Trailers – YouTube

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Release date: July 18, 1986 | Cast: Sigourney Weaver, Michael Biehn, Carrie Henn, Bill Paxton | Rotten Tomatoes: 94% on the tomatometer

Stop your grinnin’ and drop your linen! You knew it was going to be Aliens.

Picking up a sequel when you didn’t direct the previous title is a hard task, but Cameron’s bold decision gave us a bigger and (arguably) better Alien movie than the original. In fact, between this and T2, Cameron might be the best sequel director out there.

For Aliens, the xenomorphs are back. We all knew it would happen, but none more so than Ellen Ripley (Sigourney Weaver), who returns after a deep freeze to find that big corporation Weyland-Yutani is very close to rattling their nest again.

And here comes Cameron’s absolute genius in the director’s chair, building on the sci-fi horror of the first with visually terrifying xenomorphs, suffocating tension, and world-building prowess that truly takes you away from reality. Ellen Ripley may have started as a character that Cameron didn’t have a say in, but he transformed her role into an Oscar nomination-worthy performance, cemented in a sci-fi world that you’d be primed to visit again and again.

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Holiday Special 2025 – A Look Back at 2025 in Space! – YouTube

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On Episode 190 of This Week In Space, Rod Pyle and Tariq Malik look back at the past year in space — its ups, its downs, its all-arounds.

What a year it’s been, and after all the challenges and hullabaloo, we’re grateful in a post-Thanksgiving fashion to welcome Jared Isaacman, at last, as the new NASA Administrator. What he will do and how remains largely unknown, but we do believe he has the nation’s interests at heart, and the man knows people are watching.

But there are a lot of other stories and we’ve done our best to stuff as many as we can into this virtual Christmas space stocking! Please join us for this year-end roundup!

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Download or subscribe to this show at: https://twit.tv/shows/this-week-in-space.

Finally, did you know you can launch your own SpaceX rocket? Model rocket maker Estes’ stunning scale model of a Falcon 9 rocket that you can pick up now. The launchable model is a detailed recreation of the Falcon 9 and retails for $149.99. You can save 10% by using the code IN-COLLECTSPACE at checkout, courtesy of our partners collectSPACE.com.

This Week in Space covers the new space age. Every Friday we take a deep dive into a fascinating topic. What’s happening with the new race to the moon and other planets? When will SpaceX really send people to Mars?

Space author and historian

Rod Pyle is an author, journalist, television producer and Editor-in-Chief of Ad Astra magazine. He has written 18 books on space history, exploration, and development, including Space 2.0, Innovation the NASA Way, Interplanetary Robots, Blueprint for a Battlestar, Amazing Stories of the Space Age, First On the Moon, and Destination Mars

In a previous life, Rod produced numerous documentaries and short films for The History Channel, Discovery Communications, and Disney. He also worked in visual effects on Star Trek: Deep Space Nine and the Battlestar Galactica reboot, as well as various sci-fi TV pilots. His most recent TV credit was with the NatGeo documentary on Tom Wolfe’s iconic book The Right Stuff.

This Week In Space co-hostThis Week In Space co-hostTariq Malik

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Space.com Editor-in-Chief

Responsible for Space.com’s editorial vision, Tariq Malik has been the Editor-in-Chief of Space.com since 2019 and has covered space news and science for 18 years. He joined the Space.com team in 2001, first as an intern and soon after as a full-time spaceflight reporter covering human spaceflight, exploration, astronomy and the night sky. He became Space.com’s managing editor in 2009. As on-air talent has presented space stories on CNN, Fox News, NPR and others.

Tariq is an Eagle Scout (yes, he earned the Space Exploration merit badge), a Space Camp veteran (4 times as a kid, once as an adult), and has taken the ultimate “vomit comet” ride while reporting on zero-gravity fires. Before joining Space.com, he served as a staff reporter for The Los Angeles Times covering city and education beats. He has journalism degrees from the University of Southern California and New York University.

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If you’ve ever shopped for binoculars as a beginner, you’ll have probably noticed that they all look similar, they’re packed full of jargon about coatings and prisms, and the price tags range from “that’s cheaper than going out for dinner” to “I could buy a used car for that”. This is particularly apparent in the world of 10×42 binoculars — the Goldilocks size that’s just right for just about everything, from spotting birds in the garden to sweeping across the night sky.

So why should you go for a 10×42? In short, it’s the jack-of-all-trades of binocular specs; ideal if you want to look at a variety of general subjects without necessarily specializing in a particular niche. The 10x magnification gets you close enough to see detail without resulting in too much shake, and the 42mm objective lenses gather plenty of light without weighing you down. It’s no surprise that this size is the best seller across almost every brand.

But here’s the catch: not all 10x42s are created equal. The glass, coatings and materials can be the difference between “hey look, there’s a bird” to “wow, I can see every feather”. Celestron offers six models across four different ranges in this size — Outland X, Nature DX (plus an ED version), TrailSeeker (plus an ED version) and Regal ED. These range from budget-friendly to “treat yourself,” with each step up adding a little more sophistication (and a little more strain on your wallet).

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We took all six models to a nature reserve to compare them side by side, to determine which one you should invest your money in and which ones to avoid.

• Read our full reviews of the 8×42 and 12×56 variants

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From herbalists in Africa gathering plants to use as poultices to acupuncturists in China using needles to cure migraines, or Indian yogis practising meditation, traditional remedies have increasingly being shown to work, and deserve more attention and research, according to a World Health Organization official.

A historical lack of evidence, which has seen traditional practices dismissed by many, could change with more investment and the use of modern technology, according to Dr Shyama Kuruvilla, who leads the WHO Global Traditional Medicine Centre.

Dr Shyama Kuruvilla, Director of the WHO Global Traditional Medicine Centre. Photograph: Lindsay Mackenzie/WHO

Earlier this year, countries agreed the WHO should adopt a new global traditional medicines strategy for the next decade that “seeks to harness the potential contribution of TCIM [traditional, complementary and integrative medicine] to health and wellbeing based on evidence”.

It includes plans to establish a robust evidence base for traditional medicine practices, develop regulation of treatments and practitioners and, where appropriate, integrate the practices into mainstream biomedical healthcare.

“It’s super-exciting,” says Kuruvilla. “I’m not saying we know what works and what doesn’t work at scale – but I think there’s this opportunity [to find out] right now.”

Traditional medicine, defined as systems for health and wellbeing that predate “biomedicine”, comes in many guises ranging from herbal tea to India’s Ayurvedic medical system.

Many of these centuries-old practices have “huge potential”, says Kuruvilla, and can now be explored in new ways by technologies including artificial intelligence, genomics and brain scans.

Kuruvilla says Thailand is a good example of a country embracing traditional medicine, with researchers observing and documenting traditional practice, and performing randomised trials to get herbal treatments on to the country’s essential medicines list. In May, Thailand’s health ministry recommended doctors switch from some biomedicines to traditional remedies for certain conditions including muscle pain and constipation.

Kratom (Mitragyna speciosa) on sale in Bangkok, Thailand. The plant has been used in traditional medicine for centuries and was legalised in 2021. Photograph: Narong Sangnak/EPA

There have been some concerns that the WHO strategy could create a backdoor for unscientific systems such as homeopathy to enter the mainstream but Kuruvilla points out that homeopathy does not fit the WHO’s definition of traditional medicine – it was only created in the late 18th century – and that there is not strong enough evidence for the practice.

But, she says: “With all of these – with biomedicine, homeopathy, traditional medicine – if the evidence changes, I think it’s our responsibility to be open to that.”

In some countries homeopathy is used as a complementary medicine “and that’s up to the countries”, Kuruvilla says. “We have to, as WHO, just stick to the evidence.

“So I think that’s our bottom line: is this supported by robust reliable evidence, especially on safety and efficacy? And if it’s not, WHO is not supporting it, whether it is biomedicine or traditional medicine.”

Not engaging wasn’t an option, because that would mean everything goes on without any safeguardsDr Shyama Kuruvilla

WHO surveys suggest that in most countries, the majority of traditional, complementary and integrative medicine services are not part of the formal health system and are paid for by patients. They are less likely to be subject to official quality checks but are hugely popular.

“Not engaging wasn’t an option, because that would mean everything goes on without any safeguards,” Kuruvilla says, pointing to a burgeoning trillion-dollar wellness industry ranging from yoga studios to “nutraceuticals”.

The opening ceremony of the second WHO global summit on traditional medicine in New Delhi, India, on 17 December. Photograph: CBAS Films/WHO

New methods let scientists study traditional medicine “in a way that wasn’t possible before”, Kuruvilla says. Genomics might prompt new understanding of the properties of a plant, while modern scanning equipment can pick up changes in the brains of people meditating.

“Meditation was all this ‘woo-woo stuff’ but now, seeing all these advances in neuroscience and showing changes in brain waves from functional magnetic resonance imaging, which we couldn’t do before – actually being able to trace the pathways that lead to changes in health measurements – I think this is really, really exciting,” she says.

A new WHO strategic technical advisory group for traditional medicine was launched this week at a global summit in India. “This is a pivotal moment for traditional medicine. It embodies cultural heritage and national health identities, and increasingly, it constitutes a vital component of primary health care strategies,” Dr Yukiko Nakatani, WHO’s assistant director-general for health system, access and data, told the summit.

The idea, Kuruvilla suggests, is to “build a bridge” between traditional medicine and biomedicine. It is important to “find commonalities”, she says. “Showing that the science can be robust is really, really important, and especially on the patient safety aspect.”

Traditional medicine has the potential to be a “treasure trove”, Kuruvilla says. The vast numbers of people working in the field – including university-educated professionals accredited to work in clinics in China and India – could ease global workforce shortages and make a “huge contribution” to universal health coverage, she says.

Staff prepare traditional herbal medicine at a hospital in Tongren, China. Photograph: CFOTO/Future Publishing/Getty Images

In the context of aid cuts forcing countries to rethink health provision, traditional medicine could be “a way for countries also to be more self-reliant and then share those resources with each other”.

The risk of failing to invest, she says, is leaving people unable to access their preferred type of healthcare in a safe way and “the world not being able to use our shared heritage here in a way that allows us to find new holistic solutions for health and wellbeing of people and planet”.

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In the late 1970s, legendary physicist John Wheeler proposed a radical question: Exactly when does the universe notice that we’re paying attention to a quantum experiment? And does it really matter? The answer goes against everything we thought we knew.

Wheeler’s thought experiment, which eventually became a real experiment, involved the famous double-slit experiment. Let’s say you have a source of light and a screen with two thin, vertical slits. When you shine the light through the slits, the light acts like a wave. It interferes with itself, causing a ripple-like pattern on a far wall, with strips of brightness alternating with darkness. This is exactly how waves work, and if you ever find yourself in a harbor with two narrow openings, you’ll see the waves washing up onshore with a similar pattern.

Now, let’s say you make the light really weak — so weak that, eventually, only one photon at a time goes through the double slit. Amazingly, even though each individual photon acts like a particle — it hits the far wall in one specific spot — after enough photons arrive, the same interference pattern emerges. The usual conclusion is that the wave nature of a single photon interferes with itself to create the pattern.

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Now, let’s add one more layer. Let’s say you introduce a detector to the slits, to figure out which slit the photon actually passed through on its way through the screen. When you do this, the wave nature of the photon goes away. You get to see which slit the photon passed through — but it only ever acts like a particle, and you never get an interference pattern on the far wall.

When we design a quantum experiment, we must choose to investigate either the wave nature or the particle nature of photons — but we can’t do both. OK, it’s weird. But so far, it’s the standard sort of quantum weirdness.

Wheeler upped the ante. He asked what would happen if you were to introduce a delay. What if you were to insert a detector at the slits after the photon had already passed through?

Wheeler proposed a helpful analogy. Imagine a distant light source, like a quasar, that sends light traveling for billions of light-years. Some of that light heads right for us, while some beams follow a curved path through a gravitational lens, like a massive cluster. Both beams arrive on Earth at the same time, and we can set up an experiment to interfere with those beams. In that experiment, we can choose to study either the wave nature or the particle nature of light.

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Wheeler guessed the answer. He was right, and his correctness was later borne out by experiments. Even when we make a delayed choice, the photons somehow keep track of that and alter whether they’re going to make an interference pattern.

How does this work? We’re making our choice at the final leg of the light’s journey. How did the photons “know” what choice we were going to make ahead of time? It seems as if our choice in the future went back in time to alter how the photons behaved in the past.

An updated version of the experiment, known as the “delayed choice quantum eraser,” makes this even crazier. In this experiment, the photons pass through the slits. Then, the experiment decides whether to monitor the slits. Well after the photons have struck the screen, the experimenter decides to read the information. If the experimenter reads the information about which slit the photon passed through, there will never be an interference pattern. If the experiment throws away the information, an interference pattern emerges.

Remember, all of this is after the photon has already hit the screen.

Wheeler taught us how to think about this. He argued that it doesn’t make sense to talk about photons “in flight.” We only have measurements and observations — the final results of our experiments. The order of the events and what happened during the experiment itself don’t matter. Photons aren’t really in flight in the way we think of it, and the wave-particle duality of photons doesn’t make sense in the way we usually think about things.

What we get, whether particles or waves, is what we get. And it’s only once we make that measurement that nature reveals what aspect of reality to show us.

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Physicists at Silicon Quantum Computing have developed what they say is the most accurate quantum computing chip ever engineered, after building a new kind of architecture.

Representatives from the Sydney-based startup say their silicon-based, atomic quantum computing chips give them an advantage over other kinds of quantum processing units (QPUs). This is because the chips are based on a new architecture, called “14/15,” that places phosphorus atoms in silicon (named as such because they are the 14th and 15th elements in the periodic table). They outlined their findings in a new study published Dec. 17 in the journal Nature.

“It’s the smallest kind of feature size in a silicon chip,” Michelle Simmons, CEO of SQC, told Live Science in an interview. “It is 0.13 nanometers, and it’s essentially the kind of bond length that you have in the vertical direction. It’s two orders of magnitude below typically what TSMC does as its standard. It’s quite a dramatic increase in the precision.”

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The standard for testing fidelity in a quantum computing system is a routine called Grover’s algorithm. It was designed by computer scientist Lov Grover in 1996 to demonstrate whether a quantum computer can demonstrate “advantage” over a classical computer at a specific search function.

Today, it’s used as a diagnostic tool to determine how efficiently quantum systems are operating. Essentially, if a lab can reach quantum computing fidelity rates in the range of 99.0% and above, it’s considered to have achieved error-corrected, fault-tolerant quantum computing.

In February 2025, SQC published a study in the journal Nature in which the team demonstrated a 98.9% fidelity rate on Grover’s algorithm with its 14/15 architecture.

SQC achieves world-leading accuracy of Grover’s algorithm – YouTube

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In this regard, SQC has surpassed firms such as IBM and Google; although they have shown competitive results with dozens or even hundreds of qubits versus SQC’s four qubits.

IBM, Google and other prominent projects are still testing and iterating their respective roadmaps. As they scale up the qubit count, however, they’re forced to adapt their error mitigation techniques. QEC has proven to be among the most difficult to overcome bottlenecks.

But SQC scientists say their platform is so “error deficient” that it was able to break the record on Grover’s without running any error correction on top of the qubits..

“If you look at the Grover’s result that we produced at the beginning of the year, we’ve got the highest fidelity Grover album at 98.87% of the theoretical maximum and, on that, we’re not doing any error correction at all,” Simmons said.

Williams says the qubit “clusters” featured in the new 11-qubit system can be scaled to represent millions of qubits — although infrastructure bottlenecks may yet slow down progress..

“Obviously as we scale towards larger systems, we are going to be doing error correction,” said Simmons. “Every company has to do that. But the number of qubits we will need will be much smaller. Therefore, the physical system will be smaller. The power requirements will be smaller.”

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